of the verb stem ‘dureu-’(두르-). As a result the meaning of Ju Ryu Seong(周留城) designated in general ... island which was surrounded by a river water.The original sound of Ju(周) was /dyu/ and yu(留) was /lyu ... ) was /dyu/ and yu(留) was /lyu/.
Therefore in the Old Korean Ju Ryu(周留) would be pronounced as